Abrading apparatus for finishing plates



Sept. 3, 1968 A. LAMPANI ETAL 3,399,498

ABRADING APPARATUS FOR FINISHING PLATES Filed Feb. 8, 1966 2 Sheets-Sheet 1 Sept. 3, 1968 A. LAMPANI ETAL ABRADING APPARATUS FOR FINISHING PLATES 2 Sheets-Sheet 2 Filed Feb. 8, 1956 United States Patent 3,399,498 ABRADING APPARATUS FOR FINISHING PLATES Antonio Lampani, Mario Colombo, and Gianni B. Margola, Milan, Italy, assignors to Societa Ceramica Italiana Richard-Ginori S.p.A., Milan, Italy Filed Feb. 8, 1966, Ser. No. 525,990 Claims priority, application Italy, Sept. 15, 1965, 9,040/65 14 Claims. (Cl. 51145) ABSTRACT OF THE DISCLOSURE An apparatus for finishing the edges of ceramic plates comprising a finishing unit and units for feeding and removing successive plates to and from the finishing unit. The finishing unit includes a rotatable member for transporting plates from the feeding unit to the removing unit and a plurality of rotatable supports for individually supporting the plates to be finished. The finishing unit also includes means for centering and holding each plate on its support and abrading means for finishing the edges of the plate as it is held and centered on its support.

This invention relates to a machine the purpose of which is to perform finishing operations on ceramicstock made dinner plates and soup plates, that is table crockery items, the machine according to the invention being in particular, but not necessarily, reserved to become one of the operating units of installations or assemblies for an entirely mechanized cycle manufacturing of ceramic-stock crockery, as an installation actuated and operating in accordance with the copending application Ser. No. 525,991, filed Feb. 8, 1966 by Gianni B. Margola.

So far as known in this art, ceramic-stock semifinished products, in the course of further treatment which results in the finished product, undergo a finishing operation, i.e., an operation which is usually carried out after completion of the drying process for the soft pasty material round-shaped item.

The above-mentioned finishing operation has as a major purpose to ensure the smoothness and evenness of the plate round-off edge. This operation is usually carried out through abrasive means which are manually faced and contacted against the plate edge, when the plate is rapidly rotated about its axis on a spindle or plate-holder on which the plate is manually matched and centered. Said operations as carried out in accordance with the usual method, require an extended period of time and require unusual skill on the part of the operating personnel and further, satisfactory results depend on continuous care and sensitiveness on the part of the operator.

Moreover, in further accordance with the known art, plate finishing is generally carried out in the course of an intermediate step in the entire drying process, that is, on material which is considerably moist. On the contrary, in the case of an entirely mechanized installation for the manufacture of said ceramic articles, it is useful for the finishing to be done after completion of the drying process. This involves overcoming some further technical problems, and the maintenance of conditions which depends upon the practically complete dry state of the semifinished product.

' In view of the above, the object of the present invention is the provision of a machine which is suitable, entirely mechanically and automatically, for carrying out the whole cycle of operations related to said finishing, including the operations concerning the further withdrawal of dried but not finished semifinished articles ad- 3,399,498 Patented Sept. 3, 1968 vancing from a prior operating unit of the installation, the centering of said semifinished articles on a rotating spindle, the matching and evolution of abrasive means to finish the plate edge, under conditions suitable to ensure that said means are acting according to a strict uniformity and a preestablished pressure against said edge, eventually matching with the unevennesses, corrugations and the like, and finally to move away the plates for transferring them successively to the next operating units of the installation, in particular to a painting machine.

Essentially, according to the invention, the finishing machine comprises withdrawal means, operating in synchrony with means for feeding unfinished plates to the machine, suitable to further match said plates on a supporting means rotating around a vertical axis, means for actuating said supporting element according to a preestablished acceleration in order to achieve a corresponding rotation of the plate, which is previously centered on said supporting means, through displacement means which are mutually and evenly drawn near said rotation axis, in order to perfectly center the plate on the supporting element, compressing means vertically descending in said axis, for pressing the plate on the supporting means with the object to stabilize the plate on the latter, abrasive elements which in turn are progressively drawn near the edge of the plate which is so kept in position and made rotating, and apt to turn around the edge of the plate, thus carrying out the finishing and, finally, means for moving the plate away, said finishing operation unit provided with a prior moving away of said compressing means, thus permitting the further transfer to another installation operating unit.

According to a principal embodiment of the present invention, said abrasive elements are made from small and light flexible abrasive stock bands, emery cloth typically. Said abrasive bands in turn are supported on a pivoting structure which according to its feed positions compared to the plate to be finished, will oscillate thus changing the inclination of the band portion contacting the plate edge, in order that the abrasive action is practically imparted along the entire profile of said edge.

According to another embodiment of the present invention, said abrasive elements are actuated by properly adjustable equalizers, in order that the pressure at which said organs operate, and oppose against the edge to be finished, can be preestablished and will substantially be constant independently of the position attained by their supporting structure.

According to a further embodiment of the invention, said abrasive elements are arranged and tightened between properly spaced rollers, which are periodically actuated, for example, by means of a ratched gear, in order that the portion thereof contacting the edge of the further plates subjected to their action is periodically replaced, thus retaining for an extended period of time the abrasive efficiency of said means, in that the entire development of the related abrasive surfaces is exploited.

According to a preferred embodiment, the different means for facing and moving away the plates are attained through an equivalent number of turret units which rotate around vertical spindles, and the displacement and transferring of plates, as well as the difierent operations carried out by them, taking place during the rotation of said units, which is synchronized in order to attain the required sequence of said movements and operations.

The above mentioned and other specific embodiments of the machine according to the invention, as well as the advantageous technical and manufacturing effects permitted by it, will be apparent in the course of the following detailed description covering a typical execution of the present invention, designed to illustrate, but not to 3 limit, an embodiment thereof, and shownintheac companying drawing, schematically and with the omission of the individual and real structural details as well as of those means, devices and motorization, transmission, control mechanism, which by themselves can be achieved through the actual technical know-how related to the manufacturing and service of aut-omatized operating machines.

FIG. 1 shows the entire machine illustrating schematically its operative unit.

FIG. 2 is a fragmentary representation of a portion of said unit, in the course of a stage period to the real finishing operation.

As shown in FIG. 1, the finishing machine has the purpose to finish further plates P advancing from a prior unit of the installation, a drier for example, and fed, for example, by means of a conveyor belt 10, in the direction indicated by arrow 11, while a corresponding conveyor belt 12, or other equivalent means, moves the finished plates P away at an equal rate towards 13.

The machine comprises a feeding unit 14, one operating unit and a plate removing unit 16, each of said units comprising a turret and a platform which rotates around a vertical axis. According to a preferred embodiment, feeding unit 14 and plate removing unit 16 comprise respective rotating heads 17 and 18, each bearing a plurality of fork-arms 19 which rotate in the directions indicated by arrows 20 and 21. Said fork-arms 19 are actuated, through mechanical means, eccentrics, for example, or air-operated hydraulic or other means in order that the end forks 22 of fork-arms 19 successively contacting the plates to .be finished engage with lower portion of the opposite edges of the plates and then same lift up, thus removing the plates and transfer them, due to the effect of the rotating movement of the related units, to the working position on the operating unit 15, or the plate removing unit on the conveyor belt 12, the entire operation being free of deformation and practically without imparting any stress to the semifinished plates.

The operating unit 15 comprises, a rotating platform having on its periphery a plurality of similar work positions, one of which is shown in FIG. 2. The following description applies equally to all the work positions, which are evenly distributed along the periphery of said platform. The rotating movement of heads 17 and 18 of the feeding and removing units are synchronized to the rotation of platform 30 of the operating unit 15.

In each work positions, the operating unit comprises a discoidal spindle 31 (FIG. 2) supported by shaft 32 which can be rapidly rotated, for example by pulley 33 contacting driving :belt 34 running below and around the periphery of said platform. A compressing means is arranged above the discoidal spindle 31, preferably com-.

prising in turn, disc 40 having a lower surface of which 35 is lined by sufficiently flexible material, and which is supported in a rotating as well as oscillating free manner, by articulation means 36, for example, at the end 37 of an arm 38 which oscillates around a pin 39 and which is suitably counterweighed in order that said pressing means will impart its action on the underlying plate P, located on the spindle, through a force suflicient to ensure that the latter rotates, but preventing damage to it. The arm 38 is periodically and synchronously lifted, for example to the position shown in FIG. 2, by means, of cam 41, at any time that the work position gets close to the withdrawal position of the finished plate, said lift-up being maintained to overcome the position at which the feeding unit 14 places a new plate to be finished on to the discoidal spindle 31. The whole process occurs while the rotation continues towards 42 of platform 30.

After the feeding unit 14 has placed a plate P on spindle 31, and before the compressing disc has stabilized said plate on said spindle, a plurality of arms 43 hearing at their ends roller 44 lined with soft material, are mechanically drawn near the edge of said plate,

through a progressive and even movement, in order to accurately center the plate P on said spindle, thus ensuring that said plate can rapidly be rotated by said spindle while being kept at the required condition of coaxiality with it by means of the compressing disc 40 successively lowered. Said centering operation can be carried out while the spindle has not yet started rotating, or eventually at the beginning of its progressive acceleration.

When the plate brought and placed on the spindle has attained its rotating rate most suitable for the finishing operation, arm 50 is moved towards the direction shown by arrow 51, bringing an abrasive band 52 in contact with the edge 53 of the plate, thus carrying out the finishing. Said abrasive band 52, is supported by means of a suit- "able structure oscillating along a cross pin 54 and counterweighed by a mass 55, the position of which can be changed, or the weight of which can be modified, in order to permit adjustment of the pressure under which the abrasive surface is applied to the edge 53 of the plate. Moreover, the oscillating feature of the structure supporting the abrasive surface 52 permits said surface to be present according to different angles or tangent to different successive directions and inclinations compared to said edge 53, in order to complete the finishing attained by evolution around the profile of its section.

Preferably, the abrasive band 52 is arranged as a small continuous carpet or band which is supported and stretched (according to a properly preestablished and limited value tension) between rollers 56 and 57, of which one is coupled to some means, a ratched gear 58, to attain displacement of said band, as a result of each oscilalting cycle of same in order to replace in continuity the area contacting the plate edge.

In turn the movements of arm 50 are synchronized to the rotation of the platform 30, in order that the contact between abrasive band 52 and the edge of any plate will occur only after said plate has been centered on spindle 31, matched on it by means of companion disc 40 and has reached the required rotating rate. In addition said abrasive surface 52 is set apart from the plate before said compression companion disc 40 lifts up again to release the finished plate and permits it to be moved away by means of removing unit 16.

The machine is in addition fitted with suitable means for adjusting the mutual positioning of different parts for matching with plates of different sizes and/or types, for

changing the different rotating rates, of the plate-bearing spindles, for example, according to the physical characteristics of the ceramic stock to be treated, and like this.

Since the machine according to the invention has been described and illustrated only as indicative but not as a limiting example, said machine can be constructively executed with numerous different fabricating solutions, the whole always within the scope of the present invention.

We claim:

1. Apparatus for finishing the edges of ceramic plates, said apparatus comprising a finishing unit, first means for feeding plates to be finished in succession to the finishing unit, second means for removing the finished plates in succession from the finishing unit, said finishing unit comprising a movable member which transports the plates from the first means to the second means, a plurality of rotatable support means on the movable member for supporting the plates individually as they are transported, centering means carried by the movable member for centering each plate on its associated support means, means for holding each centered plate on its associated support means and abrasive means for finishing the edges of the plates as they are rotated on the support means while being transported by the movable member.

2. Apparatus as claimed in claim 1 wherein said movable member is a platform which is rotatable about a vertical axis, said plurality of rotatable support means being constituted by a plurality of angularly spaced discs at the periphery of the platform, each disc being rotatable about a respective vertical axis, the discs successively passing the first and second means as the platform is rotated.

3. Apparatus as claimed in claim 2 wherein the centering means for centering each plate on its associated support means is a plurality of elements adjacent each of the angularly spaced discs at the periphery of the platform, said elements occupying a first position in which the plate is disengaged and a second position in which the edge of the plate is engaged by said elements while the disc carrying the plate is rotated, each of said elements including a rotatable portion which rotates when the elements are in their second position and the disc carrying the plate is rotated.

4. Apparatus as claimed in claim 2 wherein the means for holding each centered plate on its associated support means is a rotatable disc member disposed above one of the angularly spaced discs at the periphery of the platform, said rotatable disc member being lowered onto the plate which has been centered on the support means whereby the rotating centered plate is held in position on its associated support means.

5. Apparatus as claimed in claim 4 wherein the platform comprises a cam, and wherein the means for holding each centered plate on its associated support means includes an arm carrying said rotatable disc member, said arm being mounted on the platform and including a cam follower, said cam follower being acted upon by the cam to alternately raise and lower the rotatable disc member whereby the rotating, centered plate is held in position on its associated support means.

6. Apparatus as claimed in claim 5 comprising a counterweight associated with the means for holding each centered plate on its associated support means, said counterweight acting to press the rotatable disc member against the rotating, centered plate.

7. Apparatus as claimed in claim 2 wherein the abrasive means for finishing the edge of the plates comprises a movable continuous band of abrasive material for acting on the edges of the plates to be finished.

8. Apparatus as claimed in claim 7 comprising a movable element carrying the movable continuous band of abrasive material, said movable element being mounted in the platform adjacent one of the angularly spaced discs and being movable toward and away from the angularly spaced disc to thereby enable finishing of different size plates.

9. Apparatus as claimed in claim 8 wherein the movable element includes means for varying the inclination of the movable continuous band of abrasive material relative to the edge of the plate to be finished whereby the entire edge may be abraded.

10. Apparatus as claimed in claim 8 wherein the movable element includes means for varying the force with which the movable continuous band of abrasive acts on the edges of the plates to be finished.

11. Apparatus as claimed in claim 10 wherein the means for varying the force with which the movable continuous band of abrasive acts on the edges of the plates is a counter-weight on the movable element.

12. Apparatus as claimed in claim 7 comprising means for moving the movable continuous band of abrasive.

13. Apparatus as claimed in claim 1 wherein the first means for feeding plates to be finished comprises a base, a rotating head mounted on the base, said rotating head including a plurality of fork arms which engage the plates, each of said fork arms transporting an individual plate to the support means on the movable member.

14. Apparatus as claimed in claim 1 wherein the second means for removing the finished plates comprises a base, a rotating head mounted on the base, said rotating head including a plurality of fork arms which engage the plates, each of said fork arms transporting an individual finished plate from the support means on the movable member.

References Cited UNITED STATES PATENTS 1,481,242 1/1924 Mueller. 2,405,417 8/ 1946 Fruth 51--145 2,489,811 11/ 1949 Perkins 51145 2,612,007 9/ 1952 Bell 51145 3,176,434 4/ 1965 Miyabayashi 5 1-215 .8 X

FOREIGN PATENTS 606,181 11/1934 Germany.

JAMES L. JONES, JR., Primary Examiner. 

